In the hydrocarbon

(d) Identify all the 120° bond angles in the molecule.

Key Concepts

Bond Angles

Bond angles are the angles formed between two adjacent bonds at a central atom in a molecule. They are crucial for understanding molecular geometry and the spatial arrangement of atoms. In hydrocarbons, bond angles can vary depending on the hybridization of the carbon atoms involved, with common angles being 109.5° for tetrahedral, 120° for trigonal planar, and 180° for linear geometries.

Hybridization

Hybridization is the concept that describes the mixing of atomic orbitals to form new hybrid orbitals, which can explain the geometry of molecular bonding. In hydrocarbons, carbon atoms can undergo sp, sp², or sp³ hybridization, leading to different bond angles. For example, sp hybridization results in a linear arrangement with 180° angles, while sp² leads to trigonal planar arrangements with 120° angles.

Molecular Geometry

Molecular geometry refers to the three-dimensional arrangement of atoms within a molecule. It is determined by the number of bonding pairs and lone pairs of electrons around the central atom. Understanding molecular geometry is essential for predicting the bond angles and overall shape of the molecule, which is particularly relevant in hydrocarbons where multiple bond types (single, double, triple) influence the structure.